The erythropoietin receptor (EpoR) is a protein that in humans is encoded by the EPORgene.[5] EpoR is a 52 kDapeptide with a single carbohydrate chain resulting in an approximately 56–57 kDa protein found on the surface of EPO responding cells. It is a member of the cytokine receptor family. EpoR pre-exists as dimers. These dimers were originally thought to be formed by extracellular domain interactions,[6] however, it is now assumed that it is formed by interactions of the transmembrane domain[7][8] and that the original structure of the extracellular interaction site was due to crystallisation conditions and does not depict the native conformation.[9] Binding of a 30 kDa ligand erythropoietin (Epo), changes the receptor's conformational change, resulting in the autophosphorylation of Jak2 kinases that are pre-associated with the receptor (i.e., EpoR does not possess intrinsic kinase activity and depends on Jak2 activity).[10][11] At present, the best-established function of EpoR is to promote proliferation and rescue of erythroid (red blood cell) progenitors from apoptosis.[5]
^Livnah O, Stura EA, Middleton SA, Johnson DL, Jolliffe LK, Wilson IA (Feb 1999). "Crystallographic evidence for preformed dimers of erythropoietin receptor before ligand activation". Science. 283 (5404): 987–90. Bibcode:1999Sci...283..987L. doi:10.1126/science.283.5404.987. PMID9974392.
^Wilson IA, Jolliffe LK (Dec 1999). "The structure, organization, activation and plasticity of the erythropoietin receptor". Current Opinion in Structural Biology. 9 (6): 696–704. doi:10.1016/S0959-440X(99)00032-9. PMID10607675.
